Joel being killed off when he was half the heart and soul of this series. The other half being Ellie.
I seriously think a better direction for this series would have been Abby seeking vengeance and Joel/Ellie having to fight her and her cohorts: another go for two longtime fan favorites. Abby's existence would have presented an inconvenience for Joel and his lie as well.
His story pretty much ended in the first game I feel. He had a great character arc. I know people love him, I do as well, but I really didnt need another Joel and Ellie adventure. Just my opinion.